In general, an anti-reflective film is mounted on a flat-panel display device such as a plasma display panel (PDP), a liquid crystal display (LCD), and the like, in order to minimize reflection of light incident from the outside.
As a method for minimizing reflection of light, there are a method of dispersing fillers such as inorganic fine particles in a resin and coating the resin on a substrate film to impart unevenness (i.e. an anti-glare (AG) coating method), a method of forming a plurality of layers having different refractive indices on a substrate film to use light interference (i.e. an anti-reflection (AR) coating method), a combination of these methods, and the like.
Among them, in the case of the AG coating method, an absolute amount of reflected light is equivalent to that in a general hard coating method, but it is possible to obtain a low-reflection effect by decreasing an amount of light entering the eyes using scattering of the light through unevenness. However, since in the AG coating method, sharpness of a screen is deteriorated due to surface unevenness, recently, the AR coating method has been variously studied.
As a film using the AR coating method, a film having a multilayer structure in which a hard coating layer (a high-refractive index layer), a low-reflective coating layer, and the like are laminated on a substrate film has been commercialized. However, in the method of forming a plurality of layers as described above, since a process of forming each of the layers is separately performed, close interlayer adhesion (interfacial adhesion) may be weak, such that scratch resistance may be deteriorated.
Further, in order to improve scratch resistance of the low-refractive layer included in the anti-reflective film, a method of adding various particles with a nanometer size (for example, silica particles, alumina particles, zeolite particles, or the like) was mainly conducted in the past. However, in the case of using the particles with a nanometer size, it was difficult to increase scratch resistance while decreasing reflectance of the low-refractive layer, and an anti-pollution property of a surface of the low-refractive layer was significantly deteriorated due to the particles with the nanometer size.
Therefore, various studies for decreasing an absolute reflection amount of light incident from the outside and improving an anti-pollution property together with scratch resistance of a surface have been conducted, but physical properties of the anti-reflective film are not sufficiently improved in spite of these studies.